Rate multiplier

ABSTRACT

A rate multiplier wherein the multiplicand is a shaft rotation and the multiplier is typically a manually inserted value. One or more code wheels having coded apertures formed therein for the passage of radiant energy are coupled to an input shaft for rotation. In one form, stationary selector wheels with decode apertures formed therein representing different multiplier values are adjusted to index with desired apertures in the code wheels to produce a pulse train representing the product. In another form, a bank of photosensors detect the radiant energy passing the code wheel apertures, and the decoding function is performed by an electromechanical switching system which establishes the desired multiplier values.

United States Patent 3,493,736 2/1970 McCarthy eta].

Francis T. Chambers, Ill Princeton, NJ.

Nov. 6, 1969 Nov. 9, 1971 Lockheed Aircraft Corporation Burbank, Calif.

Inventor Appl. No. Filed Patented Assignee References Cited UNITED STATES PATENTS 3,500,391 3/1970 Heske.. 235/103 Primary ExaminerThomas A. Robinson Attorneys-Billy G. Corber and George C. Sullivan ABSTRACT: A rate multiplier wherein the multiplicand is a shaft rotation and the multiplier is typically a manually inserted value. One or more code wheels having coded apertures formed therein for the passage of radiant energy are coupled to an input shaft for rotation. in one form, stationary selector wheels with decode apertures formed therein representing different multiplier values are adjusted to index with desired apertures in the code wheels to produce a pulse train representing the product. In another form, a bank of photosensors detect the radiant energy passing the code wheel apertures, and the decoding function is performed by an electromechanical switching system which establishes the desired multiplier values.

PATENTEUuuv 9 ISTI 3,619,587

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SHEET 5 OF 6 FRANCIS T CHAMBERS BY H lav/M Attorney INVIL'N'I'UR.

,IlI w RATE MULTIPLIER BACKGROUND OF THE INVENTION This invention relates generally to multipliers and more particularly to an electromechanical rate multiplier for multiplying data presented as a shaft rotation by a manually adjustable value ofone or more digits.

As background to understanding the invention, it should be recognized that the device is neither fully analog nor fully digital in technique, although it partakes of both. The method of coding the signal can best be described as incremental" as opposed to analog" or digital. In an analog system, some aspect of a process is varied in a measurable manner as a function of the variable it is desired to reproduce. Examples are the voltage amplitude of an electrical waveform, the duration of an electrical pulse, and the angular or linear position of a mechanical element. The process of variation is generally continuous. In a digital system, on the other hand, the process of variation is perforce incremented and each increment is itself coded so that the represented measurement must be determined by reading and translating the code increment-by-increment into units of measurement.

SUMMARY OF THE INVENTION An incremental system, such as here disclosed, generates a pulse train where the presence of each pulse signifies the addition of one increment of measurement of the variable. In one sense this can be called a degenerate digital system. In the preferred embodiments, a selectable number of pulses are generated per revolution of an input shaft by the interposition in an optical path of a rotating code wheel with apertures and a stationary selector wheel with apertures. The apertures in the rotating wheel are arranged in a code sequence while those in the stationary wheel are arranged to function as a decoder representing different multiplier values. Periodic alignment of desired apertures in the optical path permits the passage of radiant energy in the form of a pulse train wherein the number of pulses per revolution of the input shaft is selected by the stationary wheel.

It is an object of this invention to provide a relatively inexpensive and highly reliable means of implementing the process of multiplication for the special case where the multiplicand is available as a shaft rotation and the multiplier is desired to be a manually inserted value which can be readily changed from time to time either directly or remotely. The device has application, for example, in computers and registers such as for fluid metering systems used to dispense gasoline and other petroleum products. It also has application in rate control and speed monitoring equipment for vehicles and industrial machinery.

Another object of this invention is to provide an electromechanical rate multiplier having few moving parts and which is suitable for packaging as a small, compact unit.

Still another object of this invention is to provide an electromechanical rate multiplier having as its output a pulse count which may be remoted and whose accuracy is quantized.

Further and other objects will become apparent from a reading of the following detail specification especially when considered in combination with the accompanying drawings in which like numerals refer to like parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view showing schematically one embodiment of the rate multiplier;

FIG. 2 is an isometric view showing schematically a second embodiment of the rate multiplier;

FIG. 3 is a timing chart showing pulses as typically produced by the multiplier devices illustrated in FIGS. 1 and 2;

FIG. 4 is a chart showing typical shutter timing for the FIG. 2 embodiment;

FIG. 5 is a front view showing a preferred arrangement for the apertures in the code wheels;

FIG. 6 is a front view showing a preferred arrangement for the apertures in the selector wheels;

FIG. 7 is an isometric view showing schematically a third embodiment of the rate multiplier employing a drum as the code wheel;

FIG. 8 is a circuit schematic of a multilevel switch employed in the FIG. 7 device;

FIG. 9 is a timing chart showing pulses as typically produced in the FIG. 7 device; and

FIG. 10 is a fragmentary front view showing a modification of the FIG. 7 device wherein the code wheel is in the form of a disk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 and the following description assume, as an example, an application in which there is one unit of the multiplicand per revolution of the input shaft and in which a multiplier of three significant digits in the base ten system of counting is required. This is done solely for convenience in explaining the construction and operation of the invention device, as it will be evident to the reader that any desired trade-off of these parameters may be made in accordance with the teachings of the invention.

Referring specifically to FIG. 1, rate multiplier input shaft I 10 drives an intermittent motion mechanism 11 through gears 12 and 13 so as to generate at shaft 14 100 steps per revolution of input shaft 10. The intermittent motion mechanism includes a four-step per revolution sprocket 15 connected to gear 13. A transfer pinion 16 couples sprocket I5 to gear 17 on shaft 14. A lock-tooth 18, similar to those on sprocket I5, is formed on gear 17 to engage transfer pinion 19 for intermittently driving shaft 20 through gear 21 at the rate of 10 steps for every 100 steps of shaft 14. Shaft 22 is similarly driven through transfer pinion 23 and gear 24 so as to take one step for every I00 steps of shaft 14. Such intermittent motion mechanisms are well known in the art for such purposes as driving visual display counters of viz automobile odometers, in which a driven wheel typically moves 36 during the last 36 of each revolution of a driving wheel, and is thus stepped one increment (chosen to be one-tenth revolution) for every full revolution of a drive wheel. Such a system caters to the decimal or base ten system of counting utilized in the FIG. 1 device. It will be recognized that the multiplier could be im plemented for binary or other counting systems but as will be seen it provides unique advantages in the decimal or base-Id counting system.

Identical disk-shaped code wheels 25, 26 and 27 are fixedly carried one on each shaft 14, 20 and 22, respectively, to rotate in steps with the shaft on which it is mounted. Each code wheel is illuminated by a suitable source of radiant energy, such as light source 32 forming through light pipes 29, 30 and 31 separate light beams 33, 34 and 35, one for each code wheel. The size and shape of each light beam 33, 34 and 35 is determined by the design of slits 36 formed at the exit end of light pipes 29, 30 and 31 and by the requirements of the system. A plurality of apertures 28 are formed in each code wheel, as best shown in FIG. 5, to correspond to the wellknown 1-2-4-2 code for symbolizing a decimal digit utilizing binary notation. As will be seen, however, the output of each code wheel is not in fact a code in the sense of a representation in which elements at different points have different weights. It is rather a series of pulses, each of which has the same weight. Each code wheel contains a total of nine apertures distributed at 36 intervals at four different radii, such that each code wheel generates four separate trains of pulses, one with 1 pulse per revolution, two with 2 pulses per revolution, and one with 4 pulses per revolution. No 2 pulses occur at the same time and, since the nine pulses are distributed at 36 intervals, there is 1 pulse time in each revolution at which no pulse is generated. FIG. 3 is a timing chart showing a typical arrangement of the pulses from the three code wheels 25, 26 and 27 wherein l0, revolutions ofinput shaft I0 represents.

as an example, the delivery of gallons of gasoline. Time position lines 37, 38, 39, 40 and 41 on the FIG. 3 chart indicate the times at which wheel 25 generates no pulse and wheel 26 is generating a pulse. Time position line 42 on the same chart shows a time when wheels 25 and 26 generate no pulse and wheel 27 is generating a pulse.

In the implementation of FIG. 1, the pulses are generated by apertures 28 when the code wheels are in the process of stepping from one position to the next. As an aperture 28 moves through a light beam 33, 34 or 35, a radiant energy pulse 43 is formed.

Selector wheels 50, 51 and 52 are mounted adjacent code wheels 25, 26 and 27, respectively, to obstruct light passing through the apertures in the code wheels except when a code wheel aperture is aligned with a selector wheel aperture such as aperture 53 in the path of light beam 33.

Selector wheels 50, 51 and 52 have identically arranged apertures as best shown in FIG. 6 for decoding the pulse train outputs from code wheels 25, 26 and 27. These apertures, collectively identified in FIG. 6 by the reference character 54, are distributed at 36 intervals in nine of 10 equal segments on the face of each selector wheel. One such segment of each selector wheel has no apertures formed therein as in the aperture arrangement forthe code wheels. Decode apertures 54 formed in the selector wheels represent the numerals 0 through 9 of the multiplier, as indicated in drawings. It is the function of each selector wheel to select none or up to four of the pulse train outputs from its associated code wheel, depending upon the setting of the selector wheel, to provide the desired multiplier value. The selector wheel does this in accordance with the following table of functions:

The x indicates that the input so labeled is connected through to the output. In FIG. 1, this is illustrated by aperture 53 in selector wheel 50 indexing with an aperture in code wheel 25 permitting light pulse 43 to be applied to a photosensor 55 through light pipe 56.

Photosensor 55 may be a light activated silicon controlled rectifier permitting direct drive of an output counter 57 without intervening power amplification. Counter 57, of course, must be of a type which can be reset to 0 unless a eumulative total of all transactions is desired. Such counters may be typically either electronic or electromechanical. One such electromechanical counter is a Veeder-Root series I591 counter, presently available as a standard item on the open market.

Light pipes 58 and 59 cooperate with selector wheels 51 and 52 to direct light pulses passing therethrough to photosensor 55 in a like manner to that described for light pulse 43 passing selector wheel 50. As is apparent from FIG. 1, the slits 36 in light pipes 29, 30 and 31 and slits 60 formed in light pipes 56, 58 and S9 cooperate to define three separate light paths, each serving as a plane of observation for detecting coincidence with apertures in the code wheels and their associated selector wheels.

Selector wheels 50, 51 and 52 are each movable to locate any one of their IO different decode segments representing multiplier values 0 through 9 at the plane of observation. Convenient means for so positioning selector wheels 50, SI and 52 are illustrated in FIG. 1, wherein thumb wheels 61, 62 and 63 are each coupled to ratchet wheels 64, 65 and 66 which engage the outer periphery of their respective selector wheels 50, 51 and 52. Spring detents 67, 68 and 69 engage ratchet wheels 64, 65 and 66 to provide positive alignment of each selector wheel segment in its associated plane of observation.

From the foregoing description, it should be apparent that the output of any one selector wheel is selectively 0, l, 2, 3, 4, 5, 6, 7, 8 or 9 pulses per revolution of its code wheel. In the FIG. 1 device, three code wheels are utilized stepping respectively at I0, one and one-tenth revolutions per revolution of input shaft 10. Therefore, thenumber of pulses which may be generated per revolution of the input shaft may be expressed l0(a,+2a +4a +2a l (b,+2b +4b +2b,) +0. I (C +2c +4c +20 where a,, a a a, have the values 1 or 0 depending upon the position or setting of selector wheel 50 in FIG. 1, while b and c, similarly refer to the second and third selector wheels 51 and 52. This expression can take all values from 0 to 99.9, and therefore any count from 0 to 999 pulses may be generated by ten revolutions of the input shaft.

The combined outputs of the three selector wheels are fed through light pipes 56, 58 and 59 to photosensor 55, which converts the light pulses into corresponding electrical energy pulses. These electrical energy pulses drive counter 57 to provide a visual readout of the multiplier. Since, as has been shown, no pulse occurs simultaneously with any other pulse due to the absence ofa pulse from the other code wheels when one code wheel is being transferred or stepped, the counter will register each whole pulse. If the input to the multiplier is started at an arbitrary position of the code wheels and stopped at a second arbitrary position, an error of 1% count at start and ik count at stop is possible, for a total error ofil count regardless of length of computation.

In one practical application for which the rate multiplier is particularly well suited, each input shaft revolution is assumed to correspond to one gallon of gasoline, and the product, total price of a gasoline delivery, is to be rounded off to within one cent of a theoretically exact price. Where the multiplier, as in FIG. I, is adjustable in one-tenth cent steps from 0 to 99.9 cents per gallon (0 to 999 pulses in 10 gallons,) the maximum possible error of il count in making the computation is seen to be compatible with the accuracy requirements of the application. In other applications, the resolution of the multiplication process may be controlled by providing a suitable number of code wheels to give any desired accuracy without having to reset the multiplier to an exact starting position before each use.

Referring now to the FIG. 2 embodiment, there is shown a configuration for the rate multiplier which allows the intermittent motion mechanism 11 of FIG. 1 to be eliminated and the code wheels driven by the input shaft through direct gear coupling. Except for the substitution of a gating mechanism for the intermittent motion mechanism as hereinafter described, the two devices are basically alike. The purpose of the intermittent motion mechanism in the previously described FIG. 1 device is to insure that no pulse through the series of code wheels occurs at the same time as any other and that the duration of all pulses is made substantially the same. These same operating requirements can be met where the code wheels 8], 82 and 83 are directly geared to each other in 10/ 1 speed reduction, if the output of the second code wheel 82 is gated by a shutter 84 which only opens during the no pulse time of the first code wheel 81 and the third code wheel 83 is gated by a pair of shutters 85 and 86 which cooperate to open only during the combined no pulse time of the first and second code wheels 81 and 82. Various means of implementing these shutter motions are possible. A preferred method is to use the continuously rotating discs as shown in FIG. 2 which are opaque except for a slot of suitable shape and size, such as slot 87 in shutter 85.

Input shaft of the FIG. 2 rate multiplier corresponds to shaft 10 of the FIG. 1 device. Code wheel 81 is driven by this input shaft 80 through gear 88 to provide the desired turn ratio for code wheel 81 relative to the input shaft. Where code wheels 81, 82 and 83 are provided with the same aperture ar rangement as described earlier in connection with the code wheels of the FIG. 1 device, code wheel 81 will provide the same pulse producing capacity as the corresponding code wheel 25 in FIG. 1. Code wheel 81 drives shutter 84 at a l to 1 speed ratio. Shutter 84 in turn drives code wheel 82 at a to 1 speed reduction. Code wheel 82 drives shutter 85 directly at a l to l speed ratio, which in turn drives code wheel 83 through a 10 to 1 speed reduction. Shutter 84 also drives an idler 89, which drives shutter 86. Shutter 86 duplicates the action of shutter 84.

Light emitted from pipe 91 is guided through lightpath 90 to strike and attempt to pass through selector wheel 92 and code wheel 81. Selector wheel 92, as well as selector wheels 93 and 94 in the FIG. 2 device, each have apertures formed therein as shown in FIG. 6 and as described above for selector wheels 50, 51 and 52 relative to FIG. 1. These selector wheels in FIG. 2, as in the FIG. 1 device, are preferably positioned by suitable detent mechanisms so as to facilitate preselecting the number of pulses per revolution which will pass from each code wheel.

Light from pipe 91 passing selector wheel 92 and code wheel 81 is directed by pipe 96 onto photosensor 97. The output of photosensor 97 is applied to a counter 98 the same as in the FIG. 1 device. Likewise, photosensor 97 receives light traveling between light pipes 101 and 102 and light pipes 95 and 103 defining light paths 104 and 105, respectively. In the case of light path 104, light must pass the stationary selector wheel 93, the rotating code wheel 82, and the rotating shutter 84 before it can be detected by photosensor 97. The light is switched in both space and time to generate the desired pulses. A typical light pulse from code wheel 82 would exist for a large portion of one revolution of code wheel 81 were it not for the action of shutter 84 which gates it to a short duration pulse corresponding to the length of one pulse from code wheel 81. The phasing of code wheel 81 and shutter 84 is such that shutter 84 opens light path 104 at the time when code wheel 81 is at its blank or no pulse position.

Turning now to light path 105, similar considerations apply except that it is not enough to gate the light path with shutter 86 alone, since code wheel 83 may be generating a light pulse for a large portion of ten revolutions of code wheel 81. As shown in FIG. 4, shutter 85 performs the desired function of gating light path 105 to within one revolution of code wheel 81 and shutter 86, their gates it further to one standard properly phased pulse.

The timing chart of FIG. 3 is applicable to both the FIG. 1 and FIG. 2 devices. The combined outputs from each of the three light paths form a series of pulses per revolution of the input shaft representing the product of the multiplier. The number of pulses in the series so formed is determined by presetting the selector wheels to the desired multiplier value. Visual display of the product of the multiplier is obtained simply by driving a pulse counter.

Faster operating speeds can be achieved with the FIG. 2 device than with the FIG. 1 device due to elimination of the high impact loads and high accelerations inherent in intermit tent motion mechanisms. However, either configuration is well capable of meeting the speed requirements of such uses as are herein suggested. It is to be noted, for example, that the positions of the code and selector wheels in the light path may be interchanged, that the system is adaptable to various aperture codes, and that even such features as the optical method of forming the pulses may be replaced by equivalent pulseforming techniques.

In FIG. 7, there is shown an embodiment of this invention which employs a drum 110 in lieu of the disk-shaped code wheels of the FIG. 1 and FIG. 2 devices. Additionally, instead of optical decoding, the FIG. 7 device performs the decode function electromechanically.

Drum 110 is suitably secured at one end to input shaft 111 so as to rotate with the shaft. A plurality of coded slits or apertures I12 are formed in the drum for the passage of light therethrough. Apertures 112 are arranged in rows or tracks circumferentially of the drum. In a I-2-42 code sequence, four rows or tracks are provided per digit of the multiplier, and in the particular configuration shown there is a total of 12 tracks or enough for a three-digit multiplier. Thus, it will be recognized that the single drum has the same capacity as the three code wheels in the embodiments of FIGS. 1 and 2.

Radiant energy source 113 feeds light into a stationary light pipe 114 extending coaxially within drum adjacent the inner surface of the drum wall. A slit 115 is formed in the side of light pipe 114 facingthe drum wall so as to emit light through apertures 112 as they index with slit 115. This light passing through drum wall apertures 112 is detected by a bank of photosensors, one for each drum trackin photosensor head 1 16, to generate a series of pulse trains as the drum is rotated.

The relative spacing of coded apertures 112 in each of the 12 tracks is best understood by reference to FIG. 9, wherein the output pulses from three groups of four tracks each are shown for 0.1 revolution of drum 110. Each group of four tracks has a function corresponding to one of the code wheels in FIGS. 1 and 2. As seen from FIG. 9, no two pulses occur at the same time and concomitantly, no two apertures in the drum pass their respective photosensors simultaneously.

Selection of the least significant digit of the multiplier of FIG. 7 is effected by selector switch 117 picking a particular combination of up to four of the photosensors detecting the output pulses from tracks c 2c 4c and 2c,, thus generating from 0 to 9 pulses per revolution of drum 110. Selection of the intermediate digit of the multiplier is effected by selector switch 118 picking a particular combination of up to four of the photosensors detecting the output pulses from tracks b,, 212 411 and 2b,, thus generating up to 90 pulses per revolution of the drum. Similarly, the most significant digit in the three digit system shown is established by selector switch 1 19 selecting a particular combination of the four photosensors at tracks 0,, 2a 4a,, and 20,, thus generating up to 900 pulses per revolution of the drum. When the three groups of pulses are combined, it is seen that any number from O to 999 pulses may be obtained in one revolution of input shaft 111.

Photosensor head 116, as previously indicated, includes a readout cell for each track. These cells are each aligned with a corresponding track and with light-pipe slit 115 adjacent the outer surface of drum 110. As light energy from light pipe 114 passes an aperture 112 in drum 110, it is detected by a photosensor to produce a pulse. Rotation of drum 110 results in generating the series of pulses and pulse trains shown in FIG. 9.

A monolithic photosensor structure having a large PN-junction etched to form an N-type base structure with a number of P-elements, each of which acts as an independent photocell, is well suited for serving as the FIG. 7 photosensor head 116. Such photosensor devices are presently available from several sources, including the Solar Systems Division of the Tyco Company, Skokie, Ill. and Sensor Technology Inc., Van Nuys, Calif.

The desired value for each digit of the multiplier in the FIG. 7 device is obtained by selecting various combinations of the four pulse trains in each of the three groups of pulse trains shown in FIG. 9. Selector switches 117, I18 and 119 perform this decode function in a manner fully analogous to that of the selector wheels in the devices of FIGS. 1 and 2.

Selector switches 117, 118 and 119 may each be ten position, four level switches wired in the I-2-4-2 code consistent with the aperture code of drum 110 and according to the same table of functions set forth above for the selector wheels of FIGS. 1 and 2.

A typical wiring arrangement for selector switch 119 is shown in FIG. 8, it being understood that selector switches 117 and 118 may be wired in a like manner. The four inputs 120, 121, 122 and 123 from tracks a,, 2a,, 4a; and 20, on the drum are connected to appropriate contacts on the four levels 124, 125, 126 and 127 of the switch, such that wiper arms 128, I29, 130 and 131 may be moved to any of the II) switch positions by turning knob 132 to select none or any combination of pulses from each of the four tracks, thus establishing any desired multiplier value through 9 for the particular digit. The output of switch 119 appears at lead 133, which is electrically connected to wiper arms 128, 129, 130 and 131.

The combined output of the three selector switches 117, 118 and 119 is a pulse train wherein the number of pulses in the train represents the product of the multiplier device. This pulse train, when applied to a counter 135, drives the counter to present a visual product readout of the HO. 7 device, the same as previously'described for the embodiments of FIGS. 11 and 2.

A modification for the FIG. 7 device is illustrated in FIG. 10, wherein a disk-shaped code wheel 150 replaces drum 1110. Apertures 151 are formed in disk 150 in a circular pattern at 12 different radial distances from the axis of input shaft 152 to provide the same l2-track 1-2-4-2 code arrangement as described for drum 110. A bank of photosensors 1153 corresponding to photosensor head 116 in FIG. 7 detects light energy passing the coded apertures in disk 150 for pulse selection processing through a switching system like that shown in FIG. 7.

The embodiments of the invention as herein disclosed pertain to a multiplier of three significant digits utilizing a l24 2 binary code notation. This is done solely for convenience in explaining the invention. There are many code schemes which may be utilized-in implementing these teachings, and obviously the devices may be constructed to perform the multiplication function for a multiplier of any number of significant digits. The system is insensitive to starting point and the output count from any arbitrary starting point to any arbitrary stopping point will always be within one count of the theoretically correct value.

lclaim:

l. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, radiant energy source means, code wheel means coupled to the input shaft for rotation, said code wheel means being responsive to rotation for converting said radiant energy into a plurality of coded pulses, and selector means adjustable to represent different multiplier values for decoding said pulses and passing essentially only that number of said pulses which represents the desired product.

2. A device as defined in claim 1 wherein said code wheel means includes a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.

3. A device as defined in claim 2 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.

4. A device as defined in claim ll wherein said code wheel means is coupled to the input shaft through a continuous motion drive mechanism.

5. A device as defined in claim 1 wherein said code wheel means is a single code wheel coupled to the input shaft and having a plurality of rows of coded apertures formed therein for the passage of radiant energy, and said selector means includes a photosensor for each said row of coded apertures, and multicontact switch means electrically coupled to each .said photosensor for selecting various combinations of said rows to establish desired multiplier values.

6. A device as defined in claim 5 wherein said code wheel is a drum.

7. A device as defined in claim 5 wherein said code wheel is a disk.

8. A device as defined in claim 5 wherein said switch means includes a plurality of switches, one for each multiplier digit.

9. A device as defined in claim 8 wherein said plurality of switches are each adjustable to 10 different positions representing multiplier values 0 through 9.

10. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining a plurality of radiant energy paths therebetween, at least one code wheel coupled to the input shaft for rotation and having a plurality of rows of coded apertures formed therein transversely intersecting said paths to produce a plurality of coded pulses, and selector means passing only that number of said pulses which represent the desired product, said selector means being adjustable to establish different multiplier values.

11. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining at least one radiant energy path therebetween, a code wheel for each path coupled to said shaft for rotation and having a plurality of radiant energy apertures formed therein, said code wheel being positioned to transversely intersect said path so that said apertures periodically cross said path in a desired code pattern to produce a plurality of coded pulses, selector means adjustable to represent different multiplier values for decoding said pulses and passing essentially only that number of said pulses which represents the desired product, and means responsive to said detector means for counting said pulses.

112. A device as defined in claim 11 wherein a plurality of code wheels are provided, one for each digit of the multiplier, with the several code wheels being coupled to exhibit turn ratios differing one from another by the base number of the counting system.

13. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, means defining at least one path for the flow of radiant energy, code wheel means interposed in said path and coupled to the input shaft for rotation, said code wheel means having an aperture code formed therein, selector wheel means having a plurality of segments with decode apertures formed therein representing different multiplier values, said selector wheel means being movable to position selected segments thereof into said path to index with said code wheel apertures for forming a quantity of radiant energy pulses representing the product of the multiplier, and output means for counting said pulses.

14. A device as defined in claim 13 wherein said code wheel means includes a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.

115. A device as defined in claim 14 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.

16. A device as defined in claim 13 wherein said code wheel means is coupled to the input shaft through a continuous motion drive mechanism.

17. A device as defined in claim 16 including gating means operated synchronously with said drive mechanism for producing pulses of substantially constant width at the output of the multiplier.

18. A device as defined in claim 14 wherein said code wheels each have nine apertures arranged in a 1-2-4-2 code at four different radii and at nine of 10 different equiangular positions on the face thereof.

19. A rate multiplier wherein the multiplicand is a shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining at least one radiant energy path therebetween, a code wheel for each path coupled to said shaft for rotation and having a plurality of radiant energy apertures formed therein, said code wheel being positioned to transversely intersect said path so that said apertures periodically cross said path in a desired code pattern, a selector wheel positioned to transversely intersect said path, said selector wheel having a plurality of segments at least some of which contain decode apertures formed therein representing different multiplier values, said selector wheel being movable on its axis to selective positions for aligning a desired segment thereof in said path for indexing periodically with apertures in said code wheel whereby radiant energy may pass to said detector means only in the form of a pulse train in which the total number of pulses represents the product.

20. A device as defined in claim 19 employing a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.

21. A device as defined in claim 20 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.

22. A device as defined in claim 20 wherein said code wheels are coupled to each other through a continuous motion drive mechanism.

23. A device as defined in claim 22 including shutter means operated synchronously with said drive mechanism for gating the radiant energy so as to limit the width of those pulses forming said pulse train.

24. A device as defined in claim 23 wherein said code wheels are maintained in a relative phase relationship with respect to each other so as to produce nonoverlapping pulses.

25. A device as defined in claim 20 wherein said code wheels each have nine apertures arranged in a 1-2-4-2 code at four different radii and at nine of 10 different equiangular positions on the face thereof.

26. A deviceas defined in claim 25 wherein a selector wheel is employed for each code wheel and each said selector wheel has 10 equiangular segments on the face thereof with nine of the 10 segments having one to four apertures therein at four different radii corresponding to the radii for the code wheel apertures whereby multiplication values 0 through 9 may be selected for each digit of the multiplier.

27. A device as defined in claim 26 wherein said code wheels are maintained in a relative phase relationship with respect to each other so as to produce nonoverlapping pulses. 

1. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, radiant energy source means, code wheel means coupled to the input shaft for rotation, said code wheel means being responsive to rotation for converting said radiant energy into a plurality of coded pulses, and selector means adjustable to represent different multiplier values for decoding said pulses and passing essentially only that number of said pulses which represents the desired product.
 2. A device as defined in claim 1 wherein said code wheel means includes a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.
 3. A device as defined in claim 2 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.
 4. A device as defined in claim 1 wherein said code wheel means is coupled to the input shaft through a continuous motion drive mechanism.
 5. A device as defined in claim 1 wherein said code wheel means is a single code wheel coupled to the input shaft and having a plurality of rows of coded apertures formed therein for the passage of radiant energy, and said selector means includes a photosensor for each said row of coded apertures, and multicontact switch means electrically coupled to each said photosensor for selecting various combinations of said rows to establish desired multiplier values.
 6. A device as defined in claim 5 wherein said code wheel is a drum.
 7. A device as defined in claim 5 wherein said code wheel is a disk.
 8. A device as defined in claim 5 wherein said switch means includes a plurality of switches, one for each multiplier digit.
 9. A device as defined in claim 8 wherein said plurality of switches are each adjustable to 10 different positions representing multiplier values 0 through
 9. 10. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining a plurality of radiant energy paths therebetween, at least one code wheel coupled to the input shaft for rotation and having a plurality of rows of coded apertures formed therein transversely intersecting said paths to produce a plurality of coded pulses, and selector means passing only that number of said pulses which represent the desired product, said selector means being adjustable to establish different multiplier values.
 11. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining at least one radiant energy path therebetween, a code wheel for each path coupled to said shaft for rotation and having a plurality of radiant energy apertures formed therein, said code wheel being positioned to transversely intersect said path so that said apertures periodically cross said path in a desired code pattern to produce a plurality of coded pulses, selector means adjustable to represent different multiplier values for decoding said pulses and passing essentially only that number of said pulses which represents the desired product, and means responsive to said detector means for counting said pulses.
 12. A device as defined in claim 11 wherein a plurality of code wheels are provided, one for each digit of the multiplier, with the several code wheels being coupled to exhibit turn ratios differing one from another by the base number of the counting system.
 13. A rate multiplier wherein the multiplicand is an input shaft rotation, said rate multiplier comprising, means defining at least one path for the flow of radiant energy, code wheel means interposed in said path and coupled to the input shaft for rotation, said code wheel means having an aperture code formed therein, selector wheel means having a plurality of segments with decode apertures formed therein representing different multiplier values, said selector wheel means being movable to position selected segments thereof into said path to index with said code wheel apertures for forming a quantity of radiant energy pulses representing the product of the multiplier, and output means for counting said pulses.
 14. A device as defined in claim 13 wherein said code wheel means includes a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.
 15. A device as defined in claim 14 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.
 16. A device as defined in claim 13 wherein said code wheel means is coupled to the input shaft through a continuous motion drive mechanism.
 17. A device as defined in claim 16 including gating means operated synchronously with said drive mechanism for producing pulses of substantially constant width at the output of the multiplier.
 18. A device as defined in claim 14 wherein said code wheels each have nine apertures arranged in a 1-2-4-2 code at four different radii and at nine of 10 different equiangular positions on the face thereof.
 19. A rate multiplier wherein the multiplicand is a shaft rotation, said rate multiplier comprising, a source of radiant energy, detector means spaced from said source of radiant energy and defining at least one radiant energy path therebetween, a code wheel for each path coupled to said shaft for rotation and having a plurality of radiant energy apertures formed therein, said code wheel being positioned to transversely intersect said path so that said apertures periodically cross said path in a desired code pattern, a selector wheel positioned to transversely intersect said path, said selector wheel having a plurality of segments at least some of which contain decode apertures formed therein representing different multiplier values, said selector wheel being movable on its axis to selective positions for aligning a desired segment thereof in said path for indexing periodically with apertures in said code wheel whereby radiant energy may pass to said detector means only in the form of a pulse train in which the total number of pulses represents the product.
 20. A device as defined in claim 19 employing a plurality of code wheels, one for each digit of the multiplier, driven collectively at turn ratios differing one from another by the base number of the counting system.
 21. A device as defined in claim 20 wherein said code wheels are coupled to each other through an intermittent motion drive mechanism whereby one or more of said code wheels are rotated in steps.
 22. A device as defined in claim 20 wherein said code wheels are coupled to each other through a continuous motion drive mechanism.
 23. A device as defined in claim 22 including shutter means operated synchronously with said drive mechanism for gating the radiant energy so as to limit the width of those pulses forming said pulse train.
 24. A device as defined in claim 23 wherein said code wheels are maintained in a relative phase relationship with respect to each other so as to produce nonoverlapping pulses.
 25. A device as dEfined in claim 20 wherein said code wheels each have nine apertures arranged in a 1-2-4-2 code at four different radii and at nine of 10 different equiangular positions on the face thereof.
 26. A device as defined in claim 25 wherein a selector wheel is employed for each code wheel and each said selector wheel has 10 equiangular segments on the face thereof with nine of the 10 segments having one to four apertures therein at four different radii corresponding to the radii for the code wheel apertures whereby multiplication values 0 through 9 may be selected for each digit of the multiplier.
 27. A device as defined in claim 26 wherein said code wheels are maintained in a relative phase relationship with respect to each other so as to produce nonoverlapping pulses. 